人口集聚如何影响出口企业加成率:理论机制与经验证据

How Does Population Agglomeration Influence the Markups of Export Firms: Theoretical Mechanism and Empirical Evidence

本文将人口集聚纳入扩展的M-O模型中,论证了人口集聚视角下出口企业加成率动态变化的理论框架。在理论分析的基础上,利用中国工业企业数据库和海关数据库匹配数据进行实证研究,主要结论如下:(1)在其他条件不变的情况下,人口集聚会导致出口企业加成率下降。(2)分子样本异质性回归结果表明,人口集聚对资本密集型企业、外资企业、从事一般贸易企业、竞争性行业企业的负向加成率效应更大。(3)中介效应模型结果显示,人口集聚会通过“集聚经济效应”和“出口拥堵效应”影响出口企业加成率,当“出口拥堵效应”大于“集聚经济效应”会产生负向加成率效应。(4)在城市一行业层面,人口集聚存在显著的资源再配置效应,主要通过“集约边际”和“拓展边际”降低行业加成率,其中负向“企业内效应”和“进入效应”是导致出口市场拥堵和出口企业绩效恶化的主要原因。(5)“撤县设区”准自然实验、分位数回归、替代变量回归等检验均表明本文结论存在一定的稳健性。本文对当前优化城市空间布局和提升外贸竞争力具有重要启示。

This article incorporated population agglomeration into an extended M-O model,demonstrating the mechanism of dynamic change of export firms9 markups from the perspective of population agglomeration.Based on theoretical analysis,an empirical research was conducted with matched data from Annual Survey Data of Chinese Industrial Firms and Customs Database.The results show that:Under the same conditions,population agglomeration has negative effect on the markups of export firms.Sub-sample heterogeneity regression results show that population agglomeration leads to lower markups in capital intensive firms,foreigfunded firms,general trading firms and competitive industries.Mediation model results show that population agglomeration reduces the markups when export crowding effectv is greater than u agglomeration economic effectn.On the urban industry level,population agglomeration presenting a remarkable reallocation effect cuts down the markups by“intensive margin”and uextensive marginn.And negative“enterprise inside effect”and“entry effect”are main causes of an overloaded export market and deteriorative firm performance.According to the results of quasiatural experiment from“withdrawal of county districts”,quantile regression,and substitution variable regression,the conclusion of this paper has certain robustness.This paper has significant implications for optimizing urban spatial layout and promoting foreign trade competitiveness.